Perhaps I didn't say it clearly. I'm saying when the uncomfortable thoughts occur, try refocusing your thought patterns on the positive instead of dwelling on the negative. Some might use this familiar phrase, "fake it til you make it" - which isn't exactly what I want to convey but closer.

When I first started out in my polyamorous relationship, I also found those negative and mood destroying thoughts when the man I love was with his other love or was gushing about his other love. Part of our relationship involves sharing with each other our thoughts, feelings, etc about our other partners to the extent our other partners are comfortable with us sharing. While I enjoyed/enjoy listening to the joy and happiness my lover was/is experiencing, I also experienced pangs of loss and fear.

When that happened, I immediately (and internally) stopped those thoughts and focused instead on what was positive about the exchange - or if he was gone for the night and i was alone and those thoughts crept in, I focused instead on what my polyamourous relationship allowed me and what it meant to me as an individual - those values I strongly believed in that lead me to be a part of a polyamorous relationship. And I focused on the values my partner and I shared, reminding myself that him being with another love was part of being in love with a polyamorous person and that I wanted to celebrate who he was including all the polyamorous parts.

Lastly, while it felt like the relationship I knew before was ending, I focused on the fact that it wasn't truly a loss - it was a growth process that we were going through together and who we were becoming both as a couple and as individuals was actually more exciting than what we had previously.

It's a continual process - not just a one time deal.

That's what worked/works best for me - is not allowing myself to dwell on the parts that are uncomfortable. YMMV